The objective of this study was to assess the hypothesis that offspring of schizophrenics are more susceptible to perinatal complications than are offspring of normals. Correlations between perinatal and early childhood events and IQ at age 7 in the offspring of a schizophrenic group were compared with those in a matched control group and in a large unselected population. Male offspring of schizophrenics had a slightly lower mean IQ than their matched controls. Lower correlations between IQ and socio-economic indices, and higher negative correlations between IQ and certan perinatal events were found in the offspring of "continuous" schizophrenics. If these perinatal events are more negatively correlated with IQ because the children of continuous schizophrenics are specifically susceptible to them, it is possible that these factors are also influential in the later development of schizophrenia.